Ice foot development at temperate tidewater margins in Alaska

Abstract

The presence of an ice foot at the base of temperate tidewater ice cliffs has been debated for nearly 100 years. This paper presents evidence demonstrating ice feet at tidewater margins in Glacier Bay, Alaska. Ice feet are likely sources of many submarine icebergs originating at the ice margin. The cause of ice foot development is unclear, but may represent a change in fracture behavior near the bed where higher debris concentrations affect fracture propagation and calving. Ice foot formation can be favored by englacial discharge and sediment ramps along the glacier margin that can cause differential melting of the ice cliff. The presence of ice feet is important to understanding ice‐proximal sediment dynamics because they are a primary source of debris‐rich icebergs and their calving affects sediment redistribution patterns.